Effect of reagent concentration

FIG. 14-12 Effects of reagent-concentration and reagent-conversion level upon the relative values Kca in the C02-Na0H-H 0 system. [Adapted from Eckeii et at, Ind. Eng. Chem., 59f2h 41 (1967).]... 

True Affinity Labeling. Effect of Reagent Concentration. The reactions to be considered are given by Equation 1. 

Abdel-Hay et al. [31] described the determination of mefenamic acid based on its reaction in ethanolic medium with 2-nitrophenylhydrazine in the presence of dicyclohexylcarbodiimide to give an acid hydrazine, which showed intense violet color (maximum absorption at around 550 nm). The effect of reagent concentration (2-nitrophenylhydrazine-HC1, pyridine, and dicyclohexylcarbodiimide), heating temperature, and heating time were studied to optimize the reaction conditions. The method was successfully applied to the determination of mefenamic acid in pure and dosage forms, with a relative standard deviation less than 2%. 

An investigation of the effects of reagent concentration on the intensity of color produced during the chromogenic reaction between ozone and iV -phenyl-2-naphthyl-amine in o-dichlorobenzene indicated that the optimum solution concentration was O.OIM. 

Haber-Bosch process and the effect of reagent concentration. 7 Chem A... 

J. Lei, Z. Cai, and C. R. Martin, Effect of reagent concentrations used to synthesize polypyrrole on the chemical characteristics and optical and electronic properties of the resulting polymer, Svnth. Mel. 46 53 (1992). 

Kozuch S, Shaik S Kinetic-quantum chemical model for catalytic cycles the Haber-Bosch process and the effect of reagent concentration, Phys Chem All 2(26) 6032—6041, 2008. 

The catalytic activity of surfactant micelles and the effect of the concentration of reagents in micelle catalysis are tested on hydrolysis of esters of phosphorus acids [25],... 

Figure 13. Effect of varying concentrations of the NMR shift reagent Eu(fod), on methyl resonances of soyasapogenol B phenyl borate. Euffodjg was dissolved in a minimum amount of acetone-dg and added to a 2 ml solution of soyasapogenol B phenyl borate in the same solvent. Spectra were obtained at 360 MHz.

The apparent order of Vp with respect to hydrocarbon depends somewhat on the solvent, as shown in Figure 1. In fert-butylbenzene, which is inert chemically and clearly resembles the xylenes, Vp is first order in hydrocarbon, but deviations occur in o-dichlorobenzene. This principle affects generally the choice of solvents (21). Thus, even in radical oxidation, where solvent effects are much weaker than in ionic reactions, proper choice of solvent is essential if kinetic laws are to be observed over a wide range of reagent concentrations. 

Fig. 2. Effect of DNA concentration and number of PCR cycles on RAPD analysis, shown on ethidium bromide-stained agarose gels, using template DNA from a single individual titmouse (Parus bicolor) and the 10-base primer AP5a4 (5 CTGTTGCTAC 3 ). (A) Various concentrations of template DNA amplified through 45 cycles of PCR. Lanes 1-11 contain 100, 50, 20, 10, 5, 2, 1, 0.1, 0.05, 0.01, and 0.005 ng of template DNA, respectively, in 25-/

The original report32 of the titanium-catalyzed asymmetric epoxidation of allylic alcohols in 1980 has been followed by hundreds of applications, the majority of which use the initially reported conditions. In the decade since the introduction of this reaction numerous improvements have been made41. The most complete discussion of the preparative aspects of both the asymmetric epoxidation and the kinetic resolution was presented by the Sharpless group42. This paper details the effects of reagent stoichiometry and concentration, substrate concentration, aging of the catalyst and variation of oxidant, solvent and tartrate as well as workup procedures. What is particularly noteworthy in this presentation is that significant amounts of unpublished work are drawn upon to develop recommendations for successful reaction. 

Table 1 gives the dependence of ethanol and phenol concentration in the condensate and degree of conversion of organic substances on temperature. With a temperature rise from 550 to 700 the ethanol concentration decreased from 12,000 mg dm to trace levels. This corresponds with a change in the degree of ethanol conversion from 94 to almost 100%. These values are consistent with a chan in the degree of conversion of organic substances Xqqq, based on the COD of the liquid reagents before and after reaction. Phenol was analyzed in the condensate because it is an intermediate product of the reaction. Its concentration was small and decreased slightly with temperature increase. The effect of DPS concentration in the gas mixture on the yield of the oxidation process is presented in Table 2. The experiments were carried out at 600 C.

Fig. 2 Effect of ion-pair reagent concentration on separation, (a) Sorption of the ion-pair reagent as a function of concentration for reagents of different hydrophobicity (C - and Cg-sulfonates) (b) retention as a function of reagent concentration. (Reprinted from L. R. Snyder, J. J. Kirkland, and J. L. Glajch, Practical HPLC Method Development, 2nd ed., 1997, by permission of John Wiley Sons.)...

The effects of reagent and analyte concentrations on the neutralization titration curves for strong acids are shown by the two. sets of data in Table 14-2. and the... 

Mesomixing effects occur in stirred vessels when the reagent(s) feed rate is faster than the local mixing rate, resulting in a plume of reagent concentration that is not yet mixed to... 

Distilled water. Isooctane, and methanol were used as aging media. Isooctane and methanol were reagent grade and were used as received without further purification. Isooctane was selected as a relatively Inert fluid to study the effect of methanol concentration. 

Effect of Concentration of Reactants. Increase in the concentration of the hydrolyzing reagent would naturally be expected to speed up the reaction, other things being equal, but A high concentration sometimes leads to undesirable by-products. The effect of alkali concentration on the hydrolysis of allyl chloride is shown in Table 13-3. It is seen that a high alkalinity leads to an increase in the side reaction which forms diaUyl ether and a lower yield of the primary product, allyl alcohol. 

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